US3297221A - Transport mechanism for flexible materials - Google Patents

Transport mechanism for flexible materials Download PDF

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Publication number
US3297221A
US3297221A US388622A US38862264A US3297221A US 3297221 A US3297221 A US 3297221A US 388622 A US388622 A US 388622A US 38862264 A US38862264 A US 38862264A US 3297221 A US3297221 A US 3297221A
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United States
Prior art keywords
loop
pressure
tape
fluid
plates
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
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US388622A
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English (en)
Inventor
Licht Lazar
David E Brickl
Bendix H Indergard
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
International Business Machines Corp
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International Business Machines Corp
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Publication date
Priority to DENDAT1250710D priority Critical patent/DE1250710B/de
Application filed by International Business Machines Corp filed Critical International Business Machines Corp
Priority to US388622A priority patent/US3297221A/en
Priority to FR27664A priority patent/FR1442202A/fr
Application granted granted Critical
Publication of US3297221A publication Critical patent/US3297221A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B15/00—Driving, starting or stopping record carriers of filamentary or web form; Driving both such record carriers and heads; Guiding such record carriers or containers therefor; Control thereof; Control of operating function
    • G11B15/56—Driving, starting or stopping record carriers of filamentary or web form; Driving both such record carriers and heads; Guiding such record carriers or containers therefor; Control thereof; Control of operating function the record carrier having reserve loop, e.g. to minimise inertia during acceleration measuring or control in connection therewith
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B15/00—Driving, starting or stopping record carriers of filamentary or web form; Driving both such record carriers and heads; Guiding such record carriers or containers therefor; Control thereof; Control of operating function
    • G11B15/18—Driving; Starting; Stopping; Arrangements for control or regulation thereof
    • G11B15/43—Control or regulation of mechanical tension of record carrier, e.g. tape tension

Definitions

  • FIG. 1 A first figure.
  • This invention relates to techniques for transporting flexible materials and, in particular, for transporting continuous sheets of materials, such as tapes, at controlled speeds and tensions.
  • the above-mentioned vacuum column mechanism provides nonfrictional movement of material (tape) but requires a substantially completely enclosed container to maintain the vacuum, and the configuration of the tape conforms generally to the shape of the container.
  • the material is contained between two parallel plates and is acted on by a fluid (gas or liquid) under pressure which causes the material to assume a generally circular loop configuration.
  • pressure-sensitive devices are arranged to sense the pressure at various points in the mechanism to control the operation of the tape reels.
  • the amount of tape in the mechanism is maintained within predetermined bounds as the variations caused by the tape entering the mechanism from the transducer or leaving the mechanism to the transducer are compensated for by Winding or unwinding tape from the reels.
  • the tension of the material that is present within the mechanism is a function of the fluid pressure and of the loop size.
  • the mechanism is also useful in process control applications, when the transportation and tension of material is controllable by varying the rate of flow of the applied fluid, by varying the dimensions of exit and inlet ports and other fluid flow parameters.
  • the material enters and leaves the pressurized region on adjacently located fluid bearings and the loop fluid pressure is controlled by varying the gap between the entering material and the exiting material. This variation is accomplished by controlling 3,297,221 Patented Jan. 10, 1967 "ice the fluid bearing pressure.
  • an increase in fluid bearing pressure forces the entering and exiting material toward each other, reducing the size of the gap through which fluid is removed from within the loop of material and, hence, the loop pressure increases, causing the loop tension to increase. Conversely, a reduction of fluid bearing pressure causes the loop tension to decrease.
  • Another object is to provide an intermediary bufler mechanism between a low acceleration transport mechanism, such as a reel mechanism, and a high acceleration mechanism, such as a magnetic tape transducer mechanism.
  • Another object is to provide a buifer mechanism for containing a portion of tape between a tape reel mechanism and a transducer mechanism to permit the tape to be moved at higher accelerations at the transducer mechanism than are obtainable by the tape reel mechanism.
  • a further object is to provide an improved transport mechanism for flexible materials wherein fluid (gas or liquid) pressure is controllably applied to the material to cause a loop of controlled dimensions and tension to be formed.
  • a further object is to provide an improved transport mechanism for flexible materials wherein fluid (gas or liquid) pressure is controllably applied to the material to cause a loop of controlled tension to be formed and wherein the pressure is controlled by varying the applied fluid pressure or by varying the dimensions of fluid exit ports.
  • a further object is to provide an improved transport mechanism for flexible materials wherein fluid (gas or liquid) pressure is controllably applied to the material to cause a loop of controlled tension to be formed and wherein the pressure is controlled by varying the gap between the entering and exiting material.
  • a still further object is to provide an improved transport mechanism for flexible materials wherein fluid (gas or liquid) pressure is controllably applied to the material to cause a loop of controlled tension to be formed and wherein the pressure is controlled by varying the gap between the entering and exiting material by varying the pressure on fluid bearings upon which the material enters and leaves the mechanism.
  • FIG. 1 is a drawing showing a partially cut-away front view of the preferred embodiment of the invention.
  • FIG. 2 is a sectional view of the preferred embodiment of the invention taken along line 22 in FIG. 1.
  • FIG. 3 is a detailed diagram of an air bearing that is suitable for use in the invention.
  • FIG. 4 is a drawing showing a front view of a second embodiment of the invention.
  • FIG. 5 is a drawing showing a pressure control system.
  • a loop of flexible material 2 such as 3 detail in FIG. 3 where the center portion of the air bearings has a greater diameter than the end portions.
  • two nuts 14 are threaded on the end portions of the air bearing to maintain the plates 4 and 6 with the correct spacing.
  • the tape is shown in FIG. 2 to have a width that is considerably less than the distance between the plates 4 and 6; in actuality, the space between the tape and the plates is only great enough to permit the tape to be moved without significant frictional contact with the plates.
  • the tape 2 enters and leaves the assembly on air bearings 10.
  • These bearings are conventional, nonrotating, perforated cylinders having a hole drilled partially through in the axial direction.
  • a suitable air bearing is shown in FIG. 3 where two rows of apertures 16 are aligned in grooves 18 such that when air pressure is applied to the drilled opening 20, air flows through the apertures.
  • the grooves are used to cause the air to exit with substantially uniform pressure along the direction of the grooves.
  • the air bearings emit air under pressure to permit the tape to pass the bearings without physical contact.
  • an aperture 22 is provided in the bottom plate 4 to permit air to be applied under pressure. This air causes the material to assume a generally circular configuration within the assembly.
  • aperture 22 is located near bearings 10 so that pressure can be applied to the loop even though its dimensions are small.
  • the tension of the loop is dependent upon several parameters including the size of the loop, the air pressure at aperture 22, and the amount of pressure leakage in the gap between the entering and exiting material and between the material and the plates.
  • the bottom plate 4 contains two apertures 24 and 26.
  • a pair of pressure switches 28 and 30 are mounted on the bottom plate 4 to sense the pressure at apertures 24 and 26.
  • the tape loop is reduced in size (due to tape being removed from the assembly to a transducer) to where it assumes a position shown by curve 32, air pressure is removed from aperture 26 and the associated pressure switch 30 closes.
  • Current through this switch is used in a conventional manner to control a tape reel mechanism to cause the tape feed reel to unwind, supplying more tape to the assembly.
  • the air pressure within the loop is applied through aperture 24 to the associated pressure switch 28.
  • This controls the tape reel mechanism to cause the take up reel to wind, reducting the size of the loop.
  • the loop of tape increases and decreases in size as tape is supplied to or removed from the assembly to provide a buffering action between the operation of the transducer and the operation of the reels.
  • FIG. 4 A second embodiment of the invention is shown in FIG. 4.
  • the material 2 is moved through the assembly under the control of an external force and the tension of the material is controlled by the internal loop pressure.
  • the material can be processed while in the assembly; that is, the material can be dried, sprayed, coated, etc., or a liquid or gas can be applied through aperture 22 for reaction with the material.
  • a developing fluid can be applied to a photographic film in this manner.
  • the entire assembly can be immersed in a liquid or gas chamber.
  • the loop tension is controlled by either controlling the fluid (liquid or gas) pressure at aperture 22 or by controlling the fluid pressure in bearings 10. In the latter case, increasing the bearing pressure forces the entering and exiting material toward each other, re-
  • FIG. 5 shows a pressure system employing variable control elements 33 and 35 to control the fluid (gas or liquid) pressure at aperture 22 and at apertures 20 in bearings 10.
  • apertures 36 and 38 Another technique for controlling the tension of the material incorporates the use of apertures 36 and 38. These apertures permit the loop fluid pressure to escape when the loop configuration includes the apertures. That is, when the loop has a size that is less than the size determined by apertures 36, the mechanism operates in the manner described above. When the loop is large enough to encompass apertures 36, fluid leaks through these apertures, reducing the internal loop pressure and, hence, the tension of the material. Finally, when the loop is so large as to encompass apertures 38, further leakage occurs, resulting in a further decrease in tension. Obviously, the two rows of apertures 32 and 34 can be placed as close together as desired to control more precisely the loop pressure with respect to the loop size, and more or fewer rows of apertures can be employed.
  • various shaped apertures can be used instead of the circular apertures that are shown in FIG. 4.
  • the tension is gradually reduced as the loop size increases to encompass the wider portions of the wedges.
  • the plates 4 and 6 can be arranged so that they are not exactly parallel, with a greater spacing in the region of the spaces 8 than in the region of the bearings 10. In this case, leakage around the material increases when the size of the loop is increased, reducing the tension.
  • a transport mechanism for flexible strip material comprising, in combination:
  • the material guiding means are fluid bearings, comprising means for controlling the pressure of the fluid by varying the fluid bearing pressure to control the gap width, whereby the fluid leakage between the displaced portions of the material is altered.
  • At least one plate contains at least one aperture to permit fluid leakage under predetermined conditions whereby the size of the loop is controlled.
  • the pressure-sensitive device that senses the pressure at the other position provides an indication when the loop of material encompasses this position, said indication corresponding to a loop that is in excess of a second predetermined size.
  • a tape control mechanism comprising, in combination:
  • a first device for sensing the air pressure at a first region in the mechanism and for providing a predetermined indication when the pressure fails to exceed a predetermined amount
  • a second device for sensing the air pressure at a second region in the mechanism and for providing a predetermined indication when the pressure exceeds a predetermined amount.
  • a transport mechanism for flexible materials comprising, in combination:
  • two fluid bearings for conveying material to and from the mechanism, located relatively near each other between the plates with their axes perpendicular to the plates, for supplying a controllable pressure zone in the vicinity of the bearings;
  • the apparatus described in claim 10 comprising a plurality of apertures located circularly in at least one plate, approximating the desired shape of the tape loop, said apertures permitting loop fluid leakage when encompassed by the loop.
  • a tape control mechanism comprising, in combination:
  • a tape gap formed by two elongated air bearings each having at least one row of air ports, said bearings being mounted between said plates with their axes perpendicular to said plates and said rows of air ports directed substantially toward each other;
  • a first plurality of sensing devices positioned to be encompassed within a tape loop of a given size
  • a second plurality of sensing devices positioned to be encompassed within a tape loop of a given larger size
  • said first and second sensing devices being operative to indicate the presence and absence of loops of said given sizes respectively.
  • a transport mechanism for flexible strip material comprising:
  • a plurality of air bearings located between the plates for controlling the position of the open ends of a loop of material extending into the mechanism such that the opening forms a relatively small gap, and including means for applying fluid under pressure to said air bearings;
  • the flexible material being maintained circular and at a predetermined size by the control of the air pressure in the air bearings as well as in the aperture, said combination of air pressures being responsive to the pressure sensing means.

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US388622A 1964-08-10 1964-08-10 Transport mechanism for flexible materials Expired - Lifetime US3297221A (en)

Priority Applications (3)

Application Number Priority Date Filing Date Title
DENDAT1250710D DE1250710B (enrdf_load_stackoverflow) 1964-08-10
US388622A US3297221A (en) 1964-08-10 1964-08-10 Transport mechanism for flexible materials
FR27664A FR1442202A (fr) 1964-08-10 1965-08-09 Mécanisme d'entraînement de bandes souples

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US388622A US3297221A (en) 1964-08-10 1964-08-10 Transport mechanism for flexible materials

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Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3379353A (en) * 1965-10-22 1968-04-23 Cons Electrodynamics Corp Positive pressure buffer device for magnetic tape transport
US3436003A (en) * 1966-09-16 1969-04-01 Hitachi Ltd Tape supply system
US3635385A (en) * 1970-01-15 1972-01-18 Systems Resources Corp High-speed magnetic tape
US4218125A (en) * 1978-10-20 1980-08-19 Xerox Corporation Pneumatic system for supporting a photoconductive surface
EP0081631A3 (en) * 1981-12-18 1984-03-28 International Business Machines Corporation Reel-to-reel web handling apparatus
US4672092A (en) * 1983-03-30 1987-06-09 Scott Bader Company Limited Epoxide resin compositions
US4787544A (en) * 1986-05-05 1988-11-29 Jones Charles R Dancer roller

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3112473A (en) * 1955-12-30 1963-11-26 Ibm Tape storage apparatus for tape processing units
US3180547A (en) * 1962-12-06 1965-04-27 Ampex Tape transport system
US3185400A (en) * 1961-12-28 1965-05-25 Ampex Tape slack device
US3197339A (en) * 1962-04-16 1965-07-27 British Iron Steel Research Fluid cushioning systems

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3112473A (en) * 1955-12-30 1963-11-26 Ibm Tape storage apparatus for tape processing units
US3185400A (en) * 1961-12-28 1965-05-25 Ampex Tape slack device
US3197339A (en) * 1962-04-16 1965-07-27 British Iron Steel Research Fluid cushioning systems
US3180547A (en) * 1962-12-06 1965-04-27 Ampex Tape transport system

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3379353A (en) * 1965-10-22 1968-04-23 Cons Electrodynamics Corp Positive pressure buffer device for magnetic tape transport
US3436003A (en) * 1966-09-16 1969-04-01 Hitachi Ltd Tape supply system
US3635385A (en) * 1970-01-15 1972-01-18 Systems Resources Corp High-speed magnetic tape
US4218125A (en) * 1978-10-20 1980-08-19 Xerox Corporation Pneumatic system for supporting a photoconductive surface
EP0081631A3 (en) * 1981-12-18 1984-03-28 International Business Machines Corporation Reel-to-reel web handling apparatus
US4672092A (en) * 1983-03-30 1987-06-09 Scott Bader Company Limited Epoxide resin compositions
US4787544A (en) * 1986-05-05 1988-11-29 Jones Charles R Dancer roller

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DE1250710B (enrdf_load_stackoverflow)

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